Aisin Water Pumps - 5% Failure Rate?

So you could buy a cheaper pump, and replace the cover with the Toyota cover, right?
Or install thermopaste, or tape? Because that's the only difference?

And as easy as it is to pull the cover off, you could check.

 

If you've got a pump that was built right, with the double-stick thermal interface material, the cover isn't easy to pull off at all, and if you do you may have wrecked it.

I guess if you've got a pump lacking the TIM, and that's the only difference, and you have some economical access to the right kind of TIM, maybe you can take the cover off and add the TIM and reassemble and then have a more-decent pump.

 

Amazing the tiny difference that causes so many failures. Cost cutting or poor quality control on the part of the aftermarket supplier I wonder? I did replace my pump (preemptively) when I did my HG at 176K with the AISIN WPT-190 (sourced from amayama) and I've been fine and am currently about 10K miles into it.

 

I'm not sure if this has been mentioned on this forum before but be alert to the state of water pump connector (D13) when dealing with P261B code (maybe other water pump related codes as well). The leads might be loose or deformed (not sure how) causing the ECM to trip the code.

I got the P261B code recently. Did continuity, short tests and all was good. Voltage drop was also within specs. Then removed the water pump to see firsthand if the impeller was spinning, which it was if I pulled the pump away, stretching the wiring harness. Otherwise it'd just fidget. While checking the D13 connector more closely, I noticed a portion of the white plastic inside was cracked and some leads were slightly wider apart than others. Replaced the connector, put everyting back together, did about half a mile test trip and all seems to be good for now.

Thank you for your response and for sharing the amayama water pump link in another thread. I'll be getting WPT190 in about two weeks all the way from Japan and can't wait till I try a new water pump on my Prius

I've got a used OEM water pump with those two thermal paste strips on the casing. It was fairly easy to remove the case and put it back. Did a couple times today. Was actually thinking of using those strips all over the PCB. The pump gets really hot even with those two strips on them.

Yes, it might work either way

 

It's funny in that Gasket Master video, I don't think he's made up his mind if it's tape or paste: he slurs the word enogh it could be either.

 

Without finding the data sheet for the specific TIM in use there, I could be wrong, but I wouldn't be surprised if the thermal resistance from the protected component(s) to the case is a lot higher now.